Commit eeee2452 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Fix a deadlock in rpc_client_register()

Commit 38481605

 (SUNRPC: fix races on
PipeFS MOUNT notifications) introduces a regression when we call
rpc_setup_pipedir() with RPCSEC_GSS as the auth flavour.

By calling rpcauth_create() while holding the sn->pipefs_sb_lock, we
end up deadlocking in gss_pipes_dentries_create_net().
Fix is to register the client and release the mutex before calling
rpcauth_create().
Reported-by: default avatarWeston Andros Adamson <dros@netapp.com>
Tested-by: default avatarWeston Andros Adamson <dros@netapp.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: <stable@vger.kernel.org> # : 38481605: SUNRPC: fix races on PipeFS MOUNT
Cc: <stable@vger.kernel.org> # : e73f4cc0

: SUNRPC: split client creation
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 4f8568cb
...@@ -290,7 +290,7 @@ static int rpc_client_register(const struct rpc_create_args *args, ...@@ -290,7 +290,7 @@ static int rpc_client_register(const struct rpc_create_args *args,
struct rpc_auth *auth; struct rpc_auth *auth;
struct net *net = rpc_net_ns(clnt); struct net *net = rpc_net_ns(clnt);
struct super_block *pipefs_sb; struct super_block *pipefs_sb;
int err = 0; int err;
pipefs_sb = rpc_get_sb_net(net); pipefs_sb = rpc_get_sb_net(net);
if (pipefs_sb) { if (pipefs_sb) {
...@@ -299,6 +299,10 @@ static int rpc_client_register(const struct rpc_create_args *args, ...@@ -299,6 +299,10 @@ static int rpc_client_register(const struct rpc_create_args *args,
goto out; goto out;
} }
rpc_register_client(clnt);
if (pipefs_sb)
rpc_put_sb_net(net);
auth = rpcauth_create(args->authflavor, clnt); auth = rpcauth_create(args->authflavor, clnt);
if (IS_ERR(auth)) { if (IS_ERR(auth)) {
dprintk("RPC: Couldn't create auth handle (flavor %u)\n", dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
...@@ -306,16 +310,14 @@ static int rpc_client_register(const struct rpc_create_args *args, ...@@ -306,16 +310,14 @@ static int rpc_client_register(const struct rpc_create_args *args,
err = PTR_ERR(auth); err = PTR_ERR(auth);
goto err_auth; goto err_auth;
} }
return 0;
rpc_register_client(clnt); err_auth:
pipefs_sb = rpc_get_sb_net(net);
__rpc_clnt_remove_pipedir(clnt);
out: out:
if (pipefs_sb) if (pipefs_sb)
rpc_put_sb_net(net); rpc_put_sb_net(net);
return err; return err;
err_auth:
__rpc_clnt_remove_pipedir(clnt);
goto out;
} }
static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt) static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
......
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